Organization and Ownership (Details)	Dec. 31, 2016	Dec. 31, 2016 number_of_residential_units	Dec. 31, 2016 property_units	Dec. 31, 2016 ft²	Dec. 31, 2016 project	Dec. 31, 2016 tenant	Dec. 31, 2016 building	Dec. 31, 2016 property	Jan. 31, 2014 ft²
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)				14,025,856					79,000
Office properties [Member]
Real Estate Properties [Line Items]
Number of Buildings							108	4
Rentable Square Feet (unaudited)				14,025,856
Number of Tenants | tenant						549
Percentage Occupied (unaudited)	96.00%
Percentage Leased (unaudited)	97.00%
Stabilized residential properties [Member]
Real Estate Properties [Line Items]
Number of Buildings | building							1
Percentage Occupied (unaudited)	46.00%
Percentage Leased (unaudited)	56.50%
Number of units in real estate property | property_units			200
Properties held for sale [Member]
Real Estate Properties [Line Items]
Number of Buildings | property								1
Rentable Square Feet (unaudited)				67,995
Lease up properties [Member]
Real Estate Properties [Line Items]
Number of Buildings | project					1
Rentable Square Feet (unaudited)				377,000
Development properties [Member]
Real Estate Properties [Line Items]
Number of Buildings					3			3
Rentable Square Feet (unaudited)				1,100,000
Number of Residential Units | number_of_residential_units		237
Retail site [Member] | Development properties [Member]
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)				96,000